package main

import "fmt"

func myFunc(arg interface{}) {
	fmt.Println(arg)
	value, ok := arg.(string)
	if ok {
		fmt.Println(value)
	} else {
		fmt.Println("not string")
	}
}

type book struct {
	name string
}

func main() {
	b := book{"golang"}
	myFunc(b)
	myFunc("string")
}
